Monday, October 31, 2011

It will be ideal weather for trick or treating this evening with above normal temperatures and dry conditions forecast. Cloudy skies this morning will give way to afternoon sunshine along with brisk southerly winds of 30-50 km/h that will send temperatures up to the 10-11C mark this afternoon. For this evening, expect partly cloudy skies and temperatures of +5 to +8C, with diminishing southwest winds... about as good as it gets in southern MB for Halloween.

The rest of the week looks uneventful with generally dry weather and above normal temperatures. Attention will then turn to the upcoming weekend as models are indicating the potential of a Colorado low storm system moving into the Northern Plains spreading an area of rain and snow over the Dakotas and southern MB Saturday into Sunday. At this point, it's still too early to be more precise on what areas will see snow and what areas will see rain, if any. Currently, models are suggesting that the storm will track from Colorado through Nebraska into NW Minnesota with the rain/snow line setting up somewhere through the RRV. This would give a higher threat of rain over southeastern MB and snow over southwest MB. This of course will be highly dependent on the actual track and intensity of the storm which is still in question. Still, it's the first potential storm of the season for us to monitor.. and we'll stay on top of it to see how it unfolds. Stay tuned!

Sunday, October 23, 2011

Generally dry and seasonable weather is expected over southern Manitoba over the next few days as a zonal flow predominates over the central continent. Today will be a beautiful fall day over the Red River valley with sunny skies and temperatures of 10-13C (warmest in the south) although some cloud is spreading over the northern valley through the Interlake regions (towards Gimli and Grand Beach). A system passing through the Dakotas is forecast to spread cloud and some precipitation mainly south of the border Monday night into Tuesday. A ridge of high pressure will follow in the wake of that system bringing generally dry and seasonable weather for the remainder of the week.

Friday, October 14, 2011

It will be a brisk and cool weekend over southern Manitoba with increasing northwesterly winds as a strong storm system intensifies over northern Ontario this weekend. Northwest winds of 30-40 km/h Saturday will increase to 40 gusting 60 km/h Sunday as the storm system intensifies. The cool northwest winds blowing over the 13C waters of the Manitoba lakes will generate bands of lake effect showers mainly off Lake Winnipeg, with localized bands of rain to the southeast of the lakes. Brisk and cool conditions are expected through early next week with temperatures in the single digits before calmer weather by mid week.

Saturday, October 08, 2011

After several days of unseasonably warm temperatures, a cold front swept through Southern Manitoba late Friday bringing very strong winds mainly through the Red River Valley along with a few late season thunderstorms. The band of thunderstorms even produced pea to marble size hail in a few localities through the Interlake. Behind the front, very strong southerly winds developed by mid to late afternoon with gusts of 90 to 110 km/h recorded across much of the Red River Valley including Winnipeg. The winds were strong enough to bring down trees and power lines in parts of Winnipeg resulting in local power outages. The strong winds were also fanning two large brush fires south and east of Steinbach.

Some of the strongest wind gusts recorded Friday from Environment Canada and private weather monitoring sites:

At my site in Charleswood, my station's recently roof-mounted anemometer recorded a peak unadjusted wind gust of 76 km/h at 6:06 pm, the highest wind gust at my station since I installed it in Aug 2001. Note however that up until last month, my anemometer was never roof mounted but lower to the ground, so it's hard to compare with my previous wind history. Nevertheless, it was a strong wind event. Note that my website displays an adjusted wind speed that is 30% higher than the raw wind speed indicated by my weather station. This is to compensate for the less ideal exposure at my location, which is surrounded by trees and residential homes. I have found that 30% makes my wind readings more comparable to standard wind readings taken at well exposed sites at 10 metres (33 feet). Adjusting the raw peak gust value of 76 km/h by 30% would give a value of 98 km/h, which is line with peak gusts recorded in south Winnipeg Friday. I may tweak this adjustment factor down to 20-25% once surrounding trees are bare.

Thursday, October 06, 2011

It's been a windy day over Winnipeg and the Red River valley with southerly winds gusting to 70 km/h at times this afternoon. But even stronger winds are possible Friday as a cold front pushes across southern Manitoba. This front will be accompanied by a band of showers as well as some isolated thunderstorms as it moves across the Red River valley in the afternoon. Behind the front, a strong south-southwest push of cooler air will flood in, with gusts to 80 km/h at times. These strong southerly winds will persist through the afternoon before diminishing somewhat by evening. Cooler and breezy conditions are expected Saturday behind the front with lighter winds and more pleasant conditions Sunday. A few showers are possible by Thanksgiving Monday.

9:10 am UPDATE: A wind warning has been issued for the Red River valley including Winnipeg for very strong southerly winds this afternoon gusting to 90 km/h or higher. Click here for real time Winnipeg airport wind readings (in knots)

Wednesday, October 05, 2011

Today's already one for the record books.. with Winnipeg airport's 28.6C as of 1 pm surpassing the record high for Oct 5th of 28.3C set back in 1943. The question now is.. could Winnipeg set an all time high temperature today for any day in October, which currently stands at 30.5C on Oct 1 1992? The potential is there.. with a few more hours of heating left this afternoon along with gusty south to southeast winds tapping warm air to the south, lots of sunshine, and low humidity. Since 1872, Winnipeg has hit the 30C mark in October on only 3 occasions.. Oct 1 1992 (30.5C), Oct 1 1922 (30.0C) and Oct 6 1879 (30.0C) The way things are going, today will be another to add to the list. One for the record books!

3 pm update:It's official! Winnipeg records hottest October day ever with a temperature of 30.8C as of 3 pm today.(Final reading 31.1C) Previous warmest October day was Oct 1 1992 at 30.5C. Records go back to 1872. Temperature may still climb a bit for the final reading today. Temperature at my Rob's Obs site hit 31.7C at 3:39 pm (see temperature graph left).

The record day today was accompanied by gusty southerly winds up to 60 km/h, tapping 925 mb temperatures of 25C (see 19Z 925 mb plot) This, along with plenty of sunshine and low humidity, resulted in surface temperatures of 30-33C across the Red River valley. Manitoba and Canadian hot spot today was Portage La Prairie at 32.8C. See Free Press article on record setting day.

Tuesday, October 04, 2011

The summerlike conditions over southern Manitoba will continue Wednesday.. with even warmer temperatures expected. Gusty south to southeast winds up to 60 km/h will bring in unseasonably warm air from the Dakotas, with temperatures rising into the upper twenties over Winnipeg and the Red River valley. In fact, it's possible that some localities may touch the 30C mark Wednesday. In Winnipeg, a high of 28C is forecast which is very close to the day's record high of 28.3C set on Oct 5 1943. If Winnipeg hits 28C tomorrow, it will be the warmest October day in the city since Oct 1 1992 when we hit 30.5C. Note however that the record warmth will be accompanied by strong southerly winds up the valley which will gust to 60 km/h by afternoon. The unseasonably warm conditions, accompanied by low humidity and strong winds will create dangerous fire conditions.. and in fact a fire weather watch has been posted for the Red River valley in North Dakota.

Sunday, October 02, 2011

An upper ridge of high pressure over central North America will continue to bring dry and warm weather over southern Manitoba through the first week of October. Temperatures will climb into the mid 20s much of the week, some 10 degrees above the normal high of 15 for early October. The warm dry start to October this year is similar to last year which saw summerlike conditions through the Thanksgiving weekend. For today, temperatures in southern Manitoba will range from the 20 degree mark through the Interlake region to 24C along the TransCanada corridor and up to 27C near the US border. The good news is that winds today will be a lot lighter than Saturday's gusty values so conditions will be more comfortable and temperatures will feel warmer. Look for sunshine and highs in the 24-27C range the rest of the week over southern Manitoba, with increasing south winds again by Wednesday. Unsettled weather is expected by next weekend (Thanksgiving) with a few showers and cooler conditions moving in. Until then.. enjoy the fine fall weather!